1. Field of the Invention
This invention relates generally to the display of information on small display screens, and in particular to methods for displaying structured information comprising selectable and non-selectable elements, wherein some of the selectable elements have a width greater than the screen display width.
2. Description of Related Art
Pocket size or mobile devices such as cellular telephones and pagers as well as desk-top telephones are now capable of receiving and displaying structured information that originates from outside of the device. Nowadays these devices usually have display screens with varying screen sizes and consequently varying screen display widths. Thus, an author of the structured information cannot customize the layout of the information for the screen size of a specific device because the screen size is device dependent.
In view of the variations in screen size among devices, prior art solutions for displaying structured information have attempted to enable a user adapt to the information being received and to display the information in a way that makes the information usable to the user.
Currently, there are three alternative solutions to the problem of displaying text which exceeds the width of a small screen display such as those on cellular telephones or pagers. In a first method, if the text of an element 110 is longer than screen display width 101, the text is wrapped and made to flow down a display screen 125 as illustrated in FIG. 1A. In FIGS. 1A to 1D, a rectangle 108 defined by the solid lines represents display screen 125. The other elements in the structured textual information are shown simply to provide context for the following description.
In this method, the elements that do not fit on display screen 125, e.g., choices 111 to 113, are clipped and can be accessed by scrolling down vertically. This is similar to the method used by computer word processors for example. The fact that the text is structured into four elements 110 to 113 is not considered in displaying the text. Elements 110 to 113 are considered one continuous text message.
The vertical scrolling can be one line at a time, one screen display at a time (See the discussion of FIGS. 3A to 3D below), or a fraction of a screen display at a time. In this example, one line is scrolled at a time and so after a scroll operation, display screen 125 is as shown in FIG. 1B. The user sees a portion of element 110 and a portion of element 111. FIG. 1C illustrates display screen 125 after another one line scroll operation. FIG. 1D illustrates display screen displaying the fourth test element 113 which would be obtained by many one line scroll operations from the state of the display screen 125 in FIG. 3C.
As illustrated in FIGS. 1A to 1D, at any instant, the user is not able to view even a portion of all four of the choices in the list on display screen 125. In this embodiment, with a four-line display screen, the user can view at most one complete selectable element or choice. The user must scroll vertically to see the other selectable elements or choices. This makes it very hard for the user to remember what the choices are available, particularly after the user has to perform various scrolling operations to see other choices.
A second display method has been to display a message with multiple lines as a single line and automatically scroll the resulting single line horizontally across the screen display. This is similar to the way one line of information is displayed for example on Times Square in New York City.
The second method, where the text is fit on one line and scrolled horizontally, would not be at all suitable for the example discussed above with reference to FIGS. 1A to 1D. Scrolling the concatenated text of the four choices on one line, as illustrated in FIG. 2, would make the devices with small screens unusable for the user.
A last display method used is a hybrid of the two methods described above. Text is wrapped on the screen display and after a short pause, long enough for the text to be read, the text automatically scrolls vertically, usually a full screen display at a time. This display method is illustrated in FIGS. 3A to 3D where each element is displayed individually in this example.
The last method has the same pitfalls as the first method. In particular, the user is able to see only one choice at a time. The fact that the screen display scrolls automatically to the next screen display makes it harder for the user to remember the choices as the automatic scroll can occur before the user has had time to understand the choices presented to him or her.
The three scrolling methods described above are well suited to the display of unstructured textual information such as a text message. They are often used in pagers or cellular telephones that support paging.
However, as illustrated above, the methods do not work well for structured elements, such as those in a list of user choices, a menu of user options, or a list of data that are presented on a display screen which is too small to display all of the structured elements in their entirety. In each of the methods discussed above, although structured information could be used, the methods would simply process the structured information as one continuous string of text without regard to the elements within the structure.
Presenting a structured list on a small display screen presents many unresolved challenges. The reason this problem has not been solved is that up to now devices with a small display such as pagers or cellular telephones either displayed information that had been preprogrammed into the device, or displayed non-structured textual information. In the case of information that had been preprogrammed and designed into the device, such as a menu of choices pertaining to the configuration of the device, the developers who programmed these menus made sure that the information had been optimized to the device and chose the wording to make sure that the choices fit within the width of the screen display.
When information originates outside of the device, only the case of non-structured information has been implemented and the methods described above are used with good results. When structured information originates outside of the device and is meant to be displayed on devices with various display screen sizes, there has been no efficient way to layout, i.e., preprogram, the information for a particular screen display size.
Thus, a solution of the problems associated with displaying structured information on small display screens is needed before structured information, such as a list of choices and long texts (selectable elements) and short text (non-selectable elements), can be advantageously used on telephones, cellular telephones, pagers and other devices with small display screens.